Process of manufacturing titanium steel



Patented Mar. 1, 1932 UNITED STATES PATENT OFFICE PROCESS OF MANUFACTURING TITANIUM STEEL SR Drawing. Application filed March 28, 1929, Serial No. 351,115, and in Germany larch 80, 1928.

Our invention relates to improvements in the process of manufacturing titanium steel, and the object of the improvements is to provide a process by means of which a a homogeneous titanium steel is producedin an economical way;

The manufacture of titanium steel is diflicult for the reason that a homogeous distribution of the titanium or the titanium carbide formed in the steel bath is effected in a slow and imperfect way, because the diffusion of the titanium or the carbide in the molten steel bath is very slow. For example, when causing reaction of a titanium thermit, such as a 5 mixture of titanic acid, iron oxide and aluminium on the surface ofthe steel bath within the furnace or in the ladle, the titanium which may get into the bath is distributed in a very imperfect-way, and practically it is not distributed in the bath at all. Further, the major part of the aluminium contained in the titanium thermit brought on the bath is oxidized by the iron oxide contained in the slag,

so that it does not take part in the reaction. In order to bring sufiicient amounts of titanium into the steel bath, it is necessary to use a considerable excess of titanium thermit, so

that the process is uneconomical.

We have discovered that the process can be carried out in a practical and economical way by producingthe ferrotitanium separately from the manufacture of the iron bath, and adding the molten ferrotitanium to the finished iron bath.

In carrying out the process, the ferrotitanium may be brought into the iron bath by passing the same throu h the slag covering the same. But we pre er to add the liquid ferrotitanium to the steel being tap ed from the furnace or a ladle, for example by allowing the same to flow into the channel connected with the tap-hole. Thus, the steel bath containing the desired amount of carbon and refinin metals is prepared in the furnace or in the adle, and the necessary fer-rotitanium is separately prepared in a subsidiary ladle, for example by causing reaction of a mixture of titanic acid, iron oxide and aluminium. After both charges have been thus prepared they are tapped and allowed to flow together into the channel. In a modification of the process the steel bath is tapped from the furnace or a ladle and made to flow into a ladle containing a mixture of titanium thermit, the steel being preferably tapped from a plug-hole made in the bottom 0 a ladle.

In carrying out the process we may proceed as follows: a

The steel to be alloyed with titanium is deoxidized and otherwise prepared in the usual 5;, way either in the furnace or within the ladle.

In the meantime the necessary amount of titanium thermit has been filled into a second ladle, and a reaction of the said thermit has been caused in the said ladle, so that the neces- 55 sary amount of molten ferrotitanium is produced. I

Instead of preparing the molten ferrotitanium in the manner described and combining the liquids in the channel following the taphole, we may proceed so that'the molten and deoxidized steel is dischar ed in a strong current, preferably from a p ug-hole made 1n the bottom of the ladle and having an area of from 7 5 to 90 mm., into the second ladle. The liquid steel immediately ignites the titanium thermit, the reaction of the thermit takes place on the surface of-the steel bath, which is energetically intermingled by the steel flowin from the steel ladle in a strong current. Tiereby a large proportion of titanium is obtained from the titanium thermit, which titanium is uniformly alloyed to the steel collected in the second ladle.

This operation is particularly simple and as reliable, and it is economical becausethe loss of titanium by oxidation is reduced to a minimum the steel flowing from the bottom of the ladle and into the second ladle containing a very small amount of iron oxide, ordinarily in the form of slag emulsions, the said amount of iron oxide being considerably less than the oxide contained in the steel immediately flowing from the Martin furnace or the converter into the ladle. Thereby the loss of titanium by oxidation is reduced by from 30 to 40%.

Our method of adding ferrotitanium or other matter to steel baths is particularly suitable for manufacturing titanium steel .kilogrammes per sq signatures.

having a low percentage of carbon, such as 0,1%, and in which the titanium thermit being produced remains in the steel in stable so u tion. Such steel containing titanium carbide has a high strength, it has a very high limit of elasticity, it can be refined by refining metals such as chromium, manganese and the like in a far higher degree than carbon steels or titanium steels containing no carbon. For example, a steel containing about 0,1% carbon, om 0,5 to 0,8% silicon, and 0,2% titanium has a strength of 82 kilogrammes per square millimeter, as compared to the strength of 54 kilogrammes of a steel containing no titanium. The strength of the steel can be further increased by adding- 0,5% manganese and 0,5% chromium to 100 uare millimeter. The elasticity limit of the'said steel is about 80% of the strength.

The steel can be readily worked and it has a high expansion, a high contraction and a high resistance against wear.

A prerequisite of the production of a steel having the said properties is the uniform distribution of the titanium in the steel bath. By our improved process these results have been obtained.

We claim: 7

The herein described recess of manufacturing ferro-titanium, w ich consists in separately manufacturing a steel bath, and a; mixture of titanium thermit, rapidly withdrawing the steel from the bottom of the bath through a tap-hole having an area approximating from mm. toMmm and causing the molten steel to flow lnto the said mixture. 7

In testimony WAL'ifIER MATHESIUS.- HANS MATHESIUS.

whereof we hereunto aifix our 

